Rational selection of Fe2V4O13 over FeVO4 as a preferred active site on Sb-promoted TiO2 for catalytic NOX reduction with NH3. Issue 18 (28th August 2018)

• Record Type: Journal Article
• Authors: Kim, Jongsik; Kim, Dong Ho; Kwon, Dong Wook; Ha, Heon Phil
• Is Part Of: Catalysis science & technology. Volume 8:Issue 18(2018)
• Page Start: 4774
• Page End: 4787
• Publication Date: 2018-08-28
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c8cy01304g
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Fe2 V4 O13 outperforms FeVO4 as an active site for NH3 -SCR and resists SO2 /ABS/Na poisons with the inclusion of an Sb promoter. Abstract : FeVO4 (Fe1 ) is a particular class of metal vanadate that has recently been highly profiled as an active site to selectively reduce NO X with NH3 (NH3 -SCR). This primarily results from NO X /NH3 -accessible VO4 3− anions and an electronic inductive effect between the Fe and V species, leading to the formation of abundant catalytic defects available for NO X turnover. Motivated by a structural inspection of the vanadates reported to date, this study detailed the use of Fe2 V4 O13 (Fe2 ) as a novel active site deposited on anatase (TiO2 ) for NH3 -SCR. While providing the aforementioned structural benefits, Fe2 /TiO2 also enhanced the redox character as well as the number of sites accessible to NO X /NH3 over Fe1 /TiO2 because of the greater electronic inductive effect of Fe2 . Therefore, Fe2 /TiO2 converted NO X better than Fe1 /TiO2 in the presence of H2 O. To further improve the NH3 -SCR performance of Fe2 /TiO2, its catalytic surface was modified via two steps. The first step was to incorporate 1.9 wt% Sb into Fe2 /TiO2 . Sb could promote the redox feature of Fe2 /TiO2 and help its surface to preferentially interact with NH3 /NO X, thereby making the resulting Fe2 –Sb1.9 /TiO2 outperform Fe2 /TiO2 during NH3 -SCR in the presence of H2 O. The second step was to functionalize the Fe2 –Sb1.9 /TiO2 surface with SO3 2− /SO4 2− species. The resulting Fe2 –Sb1.9 /TiO2 (S) was validated to further increase redox cycling of Fe2 –Sb1.9 /TiO2, favor NO2 production from NO oxidation for fast NH3 -SCR, and hamper surface interplay with SO2 . Fe2 –Sb1.9 /TiO2 (S), therefore, showed higher NO X conversions than a control simulating a commercial catalyst during NH3 -SCR feeding H2 O and SO2 . Fe2 –Sb1.9 /TiO2 (S) also showed greater durability than the control because of its enhanced resistance to SO2, ammonium (bi)sulfates, and alkali metals.